EPITHELIAL ION TRANSPORT DEFECTS IN CYSTIC FIBROSIS: PATHOPHYSIOLOGY AND TREATMENT
Funder
National Health and Medical Research Council
Funding Amount
$290,440.00
Summary
The thin layer of fluid covering the surface of the air passages acts to protect the airway surface from drying. This fluid also allows the hair-like projections, or cilia, on the top of the airway cells to beat more effectively. The volume and composition of this fluid is determined by the movement of salt and water across the mucous membranes of the air passages. The importance of this fluid is shown by the problems that occur in Cystic Fibrosis (CF), the most common lethal inherited disease a ....The thin layer of fluid covering the surface of the air passages acts to protect the airway surface from drying. This fluid also allows the hair-like projections, or cilia, on the top of the airway cells to beat more effectively. The volume and composition of this fluid is determined by the movement of salt and water across the mucous membranes of the air passages. The importance of this fluid is shown by the problems that occur in Cystic Fibrosis (CF), the most common lethal inherited disease affecting Australians. In CF, altered salt transport causes drying of the airway surface which impairs the working of the cilia. This leads to retention of mucous in the airway with repeated bacterial infections damaging the lungs. Simple tests have been designed to directly measure the movement of salt across the surface of the nasal passage using a fine soft rubber tube. Movement of mucous in the nose is measured using other simple techniques that are currently used diagnostically. Together, these tests in the nose provide vital information about how the surface of normal human airway moves salt, water and mucous. Any differences found in CF patients will then give us a good idea of the problems found in the CF lung. We will study the interactions between calcium, sodium and chloride in the fluid lining the airways, measuring changes in salt and mucous movement. A range of testing procedures will be used in human volunteers, anaesthetised mice and isolated tissues from sheep. We have already demonstrated important links between the fluid lining the airways and salt movement, and we expect that this may lead to the development of new treatments for Cystic Fibrosis. This therapy will focus on treating the lung problems of CF patients, the major cause of disability. We anticipate that this preventative therapy may offer real benefits in the fight to cure CF.Read moreRead less
The Role Of Force-sensing Ion Channels In Melanoma Migration
Funder
National Health and Medical Research Council
Funding Amount
$553,848.00
Summary
Metastasis of melanoma cells away from the primary tumour site carries a very poor patient prognosis.This research aims to characterise a novel signalling pathway that can regulate the migration (movement) of melanoma cells. This signalling pathway depends on force-sensing platforms that can rapidly convert physical inputs from the environment into an electrical signal within the cell. We are working to understand how these force-sensors function.
The cells that produce and maintain our cartilage, known as chondrocytes, do so by sensing changes in the mechanical environment, but precisely how chondrocytes detect these changes is not known. We are investigating the role of ion channels that are opened in direct response to mechanical movements within the cartilage.This project plans to identify the specific molecules that are participating in this process and to determine if they are therapeutic targets for treatment of osteoarthritis
Structure-function Studies Of Ion Permeation And Selectivity In Recombinant Glycine Receptor Channels
Funder
National Health and Medical Research Council
Funding Amount
$331,300.00
Summary
Ligand-gated ion channels (LGICs) are members of a superfamily of receptor channels, with very significant structural and functional similarities, which play a major role in fast synaptic neurotransmission within the brain and spinal cord, and underlying the complex behaviour of the nervous system, but when dysfunctional can result in major neurological problems. Glycine is one of the two most important inhibitory neurotransmitters in the central nervous system. Impaired glycine-mediated neurotr ....Ligand-gated ion channels (LGICs) are members of a superfamily of receptor channels, with very significant structural and functional similarities, which play a major role in fast synaptic neurotransmission within the brain and spinal cord, and underlying the complex behaviour of the nervous system, but when dysfunctional can result in major neurological problems. Glycine is one of the two most important inhibitory neurotransmitters in the central nervous system. Impaired glycine-mediated neurotransmission underlies a range of inherited neurological diseases and already, it has been shown that the human disorder, familial Startle disease (hyperekplexia) occurs because of point mutations that have impaired the permeation and activation of the glycine receptor (GlyR). Similarly, certain epilepsies are now known to be caused by mutations in, or close to, the channel region in the excitatory acetylcholine receptors (AChRs), which affect channel activation and ion permeation. However, because of their very significant structural and functional similarities, information obtained in one member of the LGIC family of receptors has strong potential application to the other members and the GlyR with its simpler structure has certain advantages for investigation. The first aim of this project is to investigate how the molecular biological structure of these ion channels controls permeation, how it affects how different ions are selectively allowed to move through it and how it affects channel activation. A second related aim is to learn more about the process of desensitization of GlyR receptors, whereby a sustained presence of a high concentration of agonist can cause a reduction in receptor response. A third aim is to specifically investigate the mechanisms underlying the mode of molecular disruption resulting from two new Startle disease mutations, which, in addition to their own inherent clinical value, can also give general information about receptor function.Read moreRead less
Modelling TRPV4 Skeletal Disorders Using Human IPSCs
Funder
National Health and Medical Research Council
Funding Amount
$1,171,187.00
Summary
Inherited skeletal disorders are a significant disease burden. Many gene mutations have been defined but we only have limited understanding about how they cause the disease. We will use patient skin cells and new in vitro re-programing technology to induce them to form cartilage cells to produce “disease in a dish” models of human skeletal disorders. These models will allow us to answer questions about how specific mutations cause disease and identify potential therapies
Development Of A New High Throughput Screen For Drug Binding To HERG K+ Channels
Funder
National Health and Medical Research Council
Funding Amount
$351,320.00
Summary
Inadvertent drug block of hERG, a potassium channel in the heart, can cause cardiac arrhythmias and sudden cardiac death. Screening for hERG toxicity has become a major hurdle for development of new drugs. We will use a mutant hERG protein that has enhanced drug binding to develop a high throughput test for hERG toxicity. Identification of dangerous drugs early in the drug discovery process will save the pharmaceutical industry millions of dollars in the costs of brining new drugs to market.
The Contribution Of Subunit Interfaces To Receptor Activation In Ligand Gated Ion Channels
Funder
National Health and Medical Research Council
Funding Amount
$309,070.00
Summary
This project seeks to provide insights into new mechanisms that could be used to enhance or inhibit neuronal signalling. The family of pentameric neurotransmitter receptors that are key components in the process of neuronal signalling and are the target of this study. It will investigate the molecular motions that occur when the receptor shifts from the resting state to the activated state in the presence of neurotransmitter. This critical to understanding the normal function of these receptors ....This project seeks to provide insights into new mechanisms that could be used to enhance or inhibit neuronal signalling. The family of pentameric neurotransmitter receptors that are key components in the process of neuronal signalling and are the target of this study. It will investigate the molecular motions that occur when the receptor shifts from the resting state to the activated state in the presence of neurotransmitter. This critical to understanding the normal function of these receptors in the brain and how they can be modulated.Read moreRead less
Discovery And Development Of Better Pain Treatments
Funder
National Health and Medical Research Council
Funding Amount
$9,613,850.00
Summary
Many forms of pain remain poorly treated, leading to significant quality of life and economic losses. This Program grant will discover and characterise new peptides from cone snails and spiders that modulate specific channels in nerves that are critical to the transmission of pain signals to the brain. Using advanced chemical and structural approaches, promising leads will be optimised for potency and stability and evaluated in disease and pathway-specific models of pain to establish their clini ....Many forms of pain remain poorly treated, leading to significant quality of life and economic losses. This Program grant will discover and characterise new peptides from cone snails and spiders that modulate specific channels in nerves that are critical to the transmission of pain signals to the brain. Using advanced chemical and structural approaches, promising leads will be optimised for potency and stability and evaluated in disease and pathway-specific models of pain to establish their clinical potential.Read moreRead less
GABA(B) Receptor Modulation Of Gastrointestinal Function In Health And Disease By Alpha-Conotoxins
Funder
National Health and Medical Research Council
Funding Amount
$689,050.00
Summary
Chronic visceral pain is a common and debilitating condition arising from numerous diseases that affect our internal organs. There is a desperate need for more information about the mechanisms responsible for signalling chronic visceral pain to provide therapies and potentially find a cure for it. Our research focuses on ?-conotoxins (small peptides from marine cone snail venom) as novel potential therapeutic agents for the treatment of chronic visceral pain.
Identification Of Heterogeneity In Vasodilator Function In Human And Rat Resistance Vessels: Potential Drug Targets?
Funder
National Health and Medical Research Council
Funding Amount
$595,330.00
Summary
The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not w ....The balance between the ways that blood vessels decrease in size (constrict) and increase in size (dilate) determine how blood vessels normally function. There are many differences in the ways that blood vessels control this balance in different parts of the body. Such differences are altered in vascular diseases, such as hypertension and diabetes, which are prevalent in obesity, such that constriction generally outweighs dilation. However, what these differences are and how they occur are not well understood. While current drugs for treating vascular disease either reduce vessel constriction or increase dilation, they are not specific for individual arteries; a situation that would allow us to control vascular diseases in a very specific manner. Recently, we have described differences between the ways that individual vessels are controlled. These changes relate to differences in the way that different vessels dilate. AIMS - To further understand normal blood vessel function and the changes that occur in blood vessels in cardiovascular disease, with a focus on the ways that blood vessels dilate in normal states and in obesity-related diseases, such as in hypertension and diabetes. - The eventual aim is to identify the specific ways that arteries function, so that artery-specific drug targets can be identified to treat disease-related changes in cardiovascular disease in a very specific manner. EXPECTED OUTCOMES This project will contribute to understanding blood vessel function in health and disease. The expected eventual outcome is the identification of the mechanisms that underlie the function of different arteries in different parts of the body, so that specific individual vessel function can be targeted to treat vascular disease. Additionally, this work will also verify the relevance of the diet-induced obesity animal model, in terms of the characteristics and causes of human obesity and related cardiovascular disease.Read moreRead less